Thisstudyinvestigatestheeffectsofincreasingsoilpenetrationresistance(SPR)onseedlingmorphologyandseedlingarchitecture.WhenseedlingsofdeciduousCappadocianmaple(AcercappadocicumGled.)weregrowninagreenhouseinaloamysoilunderawiderangeofsoilcompactions,allmorphologicalvariablesstudiedchangedsignificantlywithincreasingSPR.TherelationshipsbetweenincreasingSPRandallmorphologicalresponsesexceptlateralrootlengthfollowedanegativequadraticcurve.Allbiomassvariablesexceptlateralrootbiomassshowedabell-shapedresponsewithrespecttoSPR,withamaximumbiomassvariablebetween0.6and1.2MPa,decreasingathighersoilcompactionvalues.Allallocationratiosweresignificantlyaffectedbysoilpenetrationresistance.Biomassallocationtorootswasalsoaffectedbysoilcompaction.Therewasnotasignificantrelationshipbetweenthespecificstemlengthandincreasingsoilpenetrationresistance.ThespecificrootlengthshowedtwotrendstoincreasingSPR;itfirstdecreasedinresponsetothemoderatecompactiontreatment(uptoabout1.2MPa),thenincreasedsignificantly.WeconcludedthatincreasingsoilcompactioncausedmorphologicalchangestorootandshootsectionsofA.cappadocicumseedlings.
